Well abalones get much bigger for one. A real easy way to tell an abalone apart from any other gastropod is the presence of the holes in the shell. All abalones are in the genus Haliotis if you'd like to search out more info.
I really like stomatella snails, so I've been doing my reading. Stomatella is a subfamily of Trochidae, I think. Breeding occurs when all individuals climb to a high point on the reef rock and simultaneously release sperm and eggs. You'll get a buncha baby stomatella snails, and it's great food for your filter feeders.
I was wondering myself. I wonder if they have any idea if there is anybody on the "receiving" end. Probably not, and hence they only masturbate. Pretty sad .
M.
I just found one of these guys in my tank after looking at the tank at night when the lights were off for about 2 hours. Never knew I had one...very cool. I don't even know how it hitch-hiked in either!
Very cool.. thanks for the pics.
~wings~